[This analysis of oil pollution in the waters of southeast Asia was written as part of a collaborative effort between SkyTruth team members Lucy Meyer and Brendan Jarrell.]

Our routine monitoring of the world’s oceans has led to some extraordinary findings. For example, in previous updates, we’ve identified oil slicks in traffic-heavy locations like the Strait of Malacca. But as you’ll see in this post, bilge dumps occur elsewhere in southeast Asia.

Those who follow our posts are probably familiar with how we identify vessels at sea. To new readers, let us explain what bilge dumping is and how we identify potentially responsible vessels. Bilge dumping is the disposal of waste water from a ship’s lower hull. Bilge water is supposed to be treated before it’s discharged, but sometimes vessel operators will bypass the pollution control equipment and flush oily, untreated bilge into the ocean – in direct violation of marine pollution law. We use images from satellites to monitor for illegal bilge dumping. In satellite imagery, oily bilge dumps usually form distinctive linear slicks. By matching the time of the imagery to broadcasts from a vessel tracking service called automatic identification system (AIS), we can determine the identity of vessels that appear to be causing the slicks. We used this process to identify the vessel associated with a long bilge slick in Figure 1 below.

Figure 1: A vessel shown passing through the Sunda Strait, identified as the Sungai Gerong, apparently trailing a long oily bilge slick.

This Sentinel-1 radar satellite image from July 2nd shows a slick about 177 kilometers long around the southwest tip of Banten Province, Island of Java, Indonesia (Figure 1). In the yellow box, you can see a vessel at the head of the slick. By investigating AIS broadcasts from exactEarth’s ShipView service, we identified an Indonesian oil products tanker named the Sungai Gerong as the likely vessel. The satellite scene, captured at 22:33 UTC (Coordinated Universal Time), shows a slick that closely aligns to the AIS broadcasts from the Sungai Gerong.

You’ll probably notice that the tail-end of the slick is a bit contorted and offset from the track of the Sungai Gerong. The slick’s appearance was likely influenced by ocean currents and local weather conditions between the time of the ship’s passing and when the image was taken. Global wind maps show that there were 10-15 knot winds blowing northwest up to six hours before the image was acquired. This data suggests that wind likely impacted the slick’s appearance. As a result, we believe that the Sungai Gerong is the likely source of this slick.

Using AIS, we tracked the Sungai Gerong as it traveled north through the Sunda Strait — the body of water between the Indonesian islands of Java and Sumatra — to the port of Jakarta. Similar to the Strait of Malacca, the Sunda is an important waterway that connects the Indian Ocean to the Java Sea. Though not as dense with marine traffic as the Malacca Strait, the Sunda is still subjected to pollution from vessels.

We also recently identified two suspected bilge dumps in the Philippines (Figure 2). Occurring on July 6th in the South China Sea, a 238 kilometer long slick behind the vessel in this Sentinel-1 radar image looks like a bilge dump. The Philippine island of Palawan, a popular tourist destination for its beautiful natural landscape, appears on the right side of the map frame. Another smaller slick without a known source is visible to the left of the larger slick.

Figure 2: The Ulaya makes its way through the South China Sea. Palawan Island, a part of the Philippines, can be seen to the right.

Using AIS broadcasts from ShipView, we identified the Ulaya, a Thai oil tanker, as a possible source of the slick. The last AIS broadcast from the Ulaya (seen directly above the ship) was transmitted fifteen minutes before the image was captured. These AIS broadcasts give us reason to believe that the Ulaya could be responsible for this slick. Moreover, ShipView shows that the vessel was headed towards the Port of Belawan in the Strait of Malacca with a shipment of Dangerous Goods. According to the International Maritime Organization, a United Nations agency that regulates global shipping, chemicals falling under this classification are “hazardous to marine environments.” Thus, a slick from this ship could be of greater concern than usual.

These examples show that bilge dumping continues to be a problem in the waters of southeast Asia. But with satellite imagery, anyone, anywhere can see what’s happening on the water and help to raise the alarm. We hope that our persistent and careful surveillance will inspire others to pressure policy makers, government regulators, and the shipping industry to take strong, coordinated action to stop bilge dumping.

Following up on recent reports of oil in the water off the north coast of Karawang Regency, West Java, Indonesia, SkyTruth has picked up a slick in Sentinel-1 radar imagery. In the image from July 18th, an unidentified platform (circled in red) located roughly 12 km north of the Karawang shore is shown emitting a 34.7 km-long slick into the Java Sea. A story written by the local Jakarta Post on July 18th describes state-owned energy firm Pertamina’s decision to evacuate personnel and halt operations at an offshore production rig in their Offshore Northwest Java (ONWJ) block. The evacuation was ordered after a dangerous “well kick”, or unplanned release of gas caused by low pressure in a wellbore, initiated a large slick on the 16th of July. A separate report released by the Jakarta Post five days later indicated that the Indonesian Transportation Ministry teamed up with Pertamina in response to the oil-related event, along with several other smaller entities in the area. The response vessels were able to set up a boom around the perimeter of the offshore platform. Unfortunately, this didn’t stop oil from reaching villages and beaches on West Java’s coast. Given the fact that several vessels surround the unidentified object in the Sentinel-1 image, we believe that this could be the affected drilling platform. Pertamina’s upstream director Dharmawan Samsu estimated that it will take approximately eight weeks for the oil and gas leakage to be plugged.

The unidentified platform (circled in red) can be seen leaking oil into the Java Sea. Several small vessels are in the platform’s proximity.

Key Takeaways:

SkyTruth is looking for new sources for the environmental alerts we send out.

Since relaunching Alerts in December, 2018, we’ve expanded Oil & Gas permitting to include West Virginia, Colorado, Wyoming, New Mexico, Montana and Utah. We’ve also added pollution alerts for Florida, New Mexico and New York.

We rely on our users to let us know about potential new sources for Alerts. Email your ideas to info@skytruth.org.

Introduction

Where do you start if you want to monitor the environment in an area that’s special to you? How do you find useful data? You might have a specific issue in mind and you suspect there’s relevant data online if you could only find it. Data.gov alone contains 252,892 datasets last time you checked, and much of that’s related to the environment.

You could spend days researching online datasets, and when you find something relevant figure out how to navigate the website to pull out the data you need while somehow filtering for your Area of Interest (AOI). Repeat daily.

Or, you could register for a SkyTruth Alerts account, outline and save your AOI, then go live your life while we do the heavy lifting.

Example of an Alerts email.

SkyTruth Alerts was built in 2012, originally as an in-house tool for our staff to automate receiving notifications of incidents reported to the Coast Guard’s National Response Center (NRC). The NRC is a federal emergency call center that fields initial reports for pollution and railroad incidents. They make updates available usually once a week, which we then download and add to our database. SkyTruth Alerts was soon thereafter made available to the public and expanded to include Pennsylvania Oil & Gas Permitting events, which we “scrape” from PA’s Dept. of Environmental Protection website several times a day. SkyTruth makes Alerts available to anyone, and at no charge, for the purpose of providing access to tools, data and satellite imagery that environmentalists otherwise wouldn’t have.

In 2018, Alerts was given a facelift and SkyTruth began looking for additional datasets that would help subscribers monitor their AOIs. We’ve since expanded Oil & Gas permitting to include West Virginia, Colorado, Wyoming, New Mexico, Montana and Utah. We’ve also added pollution alerts for Florida, New Mexico and New York.

Alerts In the Big Picture

Alerts is an environmental monitoring platform. In addition to receiving incident emails, users also have access to satellite imagery, relevant map layers, and the ability to annotate and share map views. Alerts is not a research platform — there are websites that do a great job with this (World Resources Institute, for one). And while we have some of the tools that allow you to monitor a species, we’re not really designed to do this task which, by the way, is already very aptly handled by sites such as iNaturalist.org. At the same time, if there’s a map layer that will help you monitor your AOI, let us know about it and we’ll see if it can be added to the set of layers we make available.

Getting Started with Alerts

What About Dataset XYZ?

We are always on the lookout for new datasets that can be a source for new Alerts, and we depend on our subscribers to help find these sources. If a dataset is important to you, it might also be important to others and we’d like to learn more. Email us at info@skytruth.org.

The number one requirement for an Alerts source is that the data must be available online. After that, to be meaningful the source needs to be related to the environment, have location information such as latitude/longitude or address, and include a date such as the incident date. Alerts don’t have to be about incidents that have already occurred. We’re also interested in new alert sources that would drive people to take action before there’s harm to the environment. Think upcoming hearings, permitting processes, etc. If the data’s online somewhere, it might make a relevant SkyTruth alert.

Our current plans are to add more oil and gas permitting states, pollution incidents and federal datasets such as those from the EPA. We love hearing from our subscribers about potential new sources and how they can be useful, and the more people who might use a source, the more likely we can add it to our database.

Coming Soon?

SkyTruth may soon be its own source of Alerts. Over the years we’ve compiled some unique datasets such as our global flaring data, which dates back to 2012. New flaring in an AOI equals a new alert, right? That’s the plan! We’re also working on algorithms that will automatically identify changes in the environment and our strategic plan includes feeding the results of Conservation Vision into Alerts. Stay tuned for progress on these fronts!

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